Buying first corvette C4 ) no start?

[louis_white]

Hi all, new member so looking forward to meeting some of you and gaining some knowledge from you all.

next week I will be taking delivery of a 1990 corvette project car. Can not wait to get this project started. Im a complete novice and never done a project before. So bought a Haynes manual some tools, the car and a membership on here! Do you recon that’s a good starter kit?

so the first thing it looks like i will need to tackle will be getting the car to start. It’s advertised as follows

''THE 5.7 V8 RUNNING GEAR IS ALL THERE TURNS OVER ON THE KEY ETC, BUT NO SPARK SO NEEDS ATTENTION SADLY, REST OF THE RUNNING GEAR LOOKS COMPLETE AND IN GOOD ORDER''

Any advice on where to start and make my way through to diagnose the spark issue, would be greatly appreciated.

Thanks all

 

[Corvette]

Well done for actually buying a Corvette. If you start a build thread in project section all the C4 boys will post with advice. Non starter? Sounds like you need advice from ‘Redlevel’ on here.

 

[Oneball]

Ooh well done. In the tools you’ve got do you have a multimeter for measuring voltage, resistance and current?

 

[rubyragtop]

Most persons suffering this problem with an L98 engine find that the ignition module has died. It is worth checking yourself that there is no spark. Easiest way is to pull a lead from one of the plugs, insert a spare plug (or remove one from the engine) and lay it against the block. Get someone to spin the engine over on the key and check for spark at the plug. Also, read the Haynes manual to see how to get fault codes from the Vette. This might give a clue to the cause.

 

[louis_white]

Well done for actually buying a Corvette. If you start a build thread in project section all the C4 boys will post with advice. Non starter? Sounds like you need advice from ‘Redlevel’ on here.

Thanks, I will 100% be doing a build thread, toying with the idea of documenting the build via YouTube also

 

[louis_white]

Ooh well done. In the tools you’ve got do you have a multimeter for measuring voltage, resistance and current?

Thanks bud, unfortunately not yet just some very basic tools for now, still along way to go, would you say the multimeter should be the next thing on my list?

 

[louis_white]

Most persons suffering this problem with an L98 engine find that the ignition module has died. It is worth checking yourself that there is no spark. Easiest way is to pull a lead from one of the plugs, insert a spare plug (or remove one from the engine) and lay it against the block. Get someone to spin the engine over on the key and check for spark at the plug. Also, read the Haynes manual to see how to get fault codes from the Vette. This might give a clue to the cause.

Thanks really appreciate this, will definitely give this a go. I was up late watching YouTube videos last night and your correct seems a common problem with the L98. I’ll start with your tip and see if it sparks at all.

 

[JonnyC4]

If the battery was disconnected, you can't run the codes to check what the problem is. So you need to trouble shoot all points. Also buy an original service manual.

My experiences is also, check all groundings.

If you need a C4 specialist, contact Keith at Eurovettes, he knows a lot about this generations.

 

[Oneball]

Thanks bud, unfortunately not yet just some very basic tools for now, still along way to go, would you say the multimeter should be the next thing on my list?

Depends on what tools you’ve already got? Seeing as we’re looking at ignition have you got a spark plug wrench? There’s two normal sizes but I’m not sure what’s correct for a C4 hopefully someone else can advise.

Likewise hopefully someone can advise: I think most fastenings on a C4 are metric but most of the engine is imperial.

Multimeters are always useful and a must at some point, I’d go for something like this.

Clarke CDM10C Digital Multimeter – 5 Function - Machine Mart - Machine Mart

www.machinemart.co.uk

 

[Redlevel]

Hi..
I'm Steve that chatted to you on Fb before.
First thing I'd check after sticking a spare plug into a plug cap and holding it against some earthed part, ..is the coil and it's connections are connected ok.
The coil is an open frame device fitted into the top of the distributor cap easily accessed when you remove the end of the plenum cover atop the distributor.
Forgetting the written word in the ad, you need to investigate yourself. The L98 isn't so complex once you get into it, so don't lose heart.
You need to ascertain for yourself that there is definately no spark.
If that's the case, it may well be the ignition module inside the dist. as previously advised. Again, its easily accessed as well as the condenser in there and they aren't expensive Keith Beschi or Rockauto can supply fairly quickly.
If they can't get a condenser to you, the only place I found that has them is Corvette Central in the USA.
I had an intermittant spark problem ages ago and ended up replacing all my items in the ignition side. When I removed my dist cap, the rotor arm crumbled to dust!
Sorry I cant be more specific at this time, but keep us posted here or on Fb on your progress..
Cheers..

 

[Redlevel]

Behind the L98's distributor is the oil pressure sensor and attached to this is the oil pressure switch.
When you turn the key to start, the ecu provides a 12v feed to the fuel pump to pressurize the fuel rail to 45psi.
At this point, the motor fires, and once the oil pressure comes up, the oil pressure switch closes and sends its own 12v feed to the fuel pump to keep the motor running.
The function of this oil pressure switch is to kill the motor in the event of sudden oil pressure loss which is bad for the bearings etc..
Cool, huh?

 

[Redlevel]

There is also a nasty thing called vats which is a security thing which will not allow the car to start if someone tries to frig it.
In your ignition key, there is a wee resistor pellet which is matched to the vats system on your car. Any mismatch and nothing will work.
As your car turns over, I'd discount this.
Don't worry too much about any codes you car shows at this time. If you can get it started, get it warmed up then stop it and disconnect the battery briefly to clear the codes, any serious ones will come back.
Corvettes do not like being idle and will show their displeasure by scaring you with lots of codes if left too long, its what they do!
Codes are easy to read with a paper clip in the diagnostic socket (above your right knee under the dash).
Good luck!

 

[louis_white]

Hey Steve, thank you so much. Honestly mate I already know having yourself and members like you is going to be a god send when I get this car

definitely will keep you updated and I’ll probably continue to bug you about other issues I find

There is also a nasty thing called vats which is a security thing which will not allow the car to start if someone tries to frig it.
In your ignition key, there is a wee resistor pellet which is matched to the vats system on your car. Any mismatch and nothing will work.
As your car turns over, I'd discount this.
Don't worry too much about any codes you car shows at this time. If you can get it started, get it warmed up then stop it and disconnect the battery briefly to clear the codes, any serious ones will come back.
Corvettes do not like being idle and will show their displeasure by scaring you with lots of codes if left too long, its what they do!
Codes are easy to read with a paper clip in the diagnostic socket (above your right knee under the dash).
Good luck!

good to know the fault codes will find there way back to me. Thanks buddy, I’ve heard a lot about the VATS issues. Car should be here soon so I pray it’s one of the easier fixes so I can move on to the many other faults I’m sure it will have but hey that’s why I bought the thing, for the fun or repairing and learning to repair. Good to know there’s knowledgable members on here like your self for guidance and support

 

[Redlevel]

I changed a lot like deleting the AIR, the whole A/C system, most of the vacuum lines, the whole evap system and a few others including the radio and speakers.

 

[Redlevel]

Engine pics

 

[louis_white]

I changed a lot like deleting the AIR, the whole A/C system, most of the vacuum lines, the whole evap system and a few others including the radio and speakers.
View attachment 8191

Wow looks great. So you saying if you can’t fix it rip it out

 

[Coffeeboy]

Hi all, new member so looking forward to meeting some of you and gaining some knowledge from you all.

next week I will be taking delivery of a 1990 corvette project car. Can not wait to get this project started. Im a complete novice and never done a project before. So bought a Haynes manual some tools, the car and a membership on here! Do you recon that’s a good starter kit?

so the first thing it looks like i will need to tackle will be getting the car to start. It’s advertised as follows

''THE 5.7 V8 RUNNING GEAR IS ALL THERE TURNS OVER ON THE KEY ETC, BUT NO SPARK SO NEEDS ATTENTION SADLY, REST OF THE RUNNING GEAR LOOKS COMPLETE AND IN GOOD ORDER''

Any advice on where to start and make my way through to diagnose the spark issue, would be greatly appreciated.

Thanks all

Hi is it a red one from Bristol ? The guys in the club are top notch and have helped me out no end with my first vette wish you luck and I also recommend Keith very well priced and very helpful

 

[louis_white]

Hi is it a red one from Bristol ? The guys in the club are top notch and have helped me out no end with my first vette wish you luck and I also recommend Keith very well priced and very helpful

Hi bud, it is yes. Been watching it for some time and decided to pull the trigger and go for it, wish me luck
I can see I’m part of a great community already

who’s keith then, does he supply parts? Thanks for the recommendation

 

[Coffeeboy]

Hi bud, it is yes. Been watching it for some time and decided to pull the trigger and go for it, wish me luck
I can see I’m part of a great community already

who’s keith then, does he supply parts? Thanks for the recommendation

Hi yea Keith at eurovettes I got my c4 from the same place as yours I had a good look over yours (was the one I went to see) but ended up with the black one he had as it’s 85 and figured only 5 yrs till it’s tax and mot exempt and he cut me a good deal on it all the help you get on here you will have it up and running in no time !! Don’t do the same as me on you tube and scare yourself !!!
He sells all his cars as non runners that’s how I bought mine and I put battery on and 5 gallons of fuel and off it went

 

[louis_white]

Hi yea Keith at eurovettes I got my c4 from the same place as yours I had a good look over yours (was the one I went to see) but ended up with the black one he had as it’s 85 and figured only 5 yrs till it’s tax and mot exempt and he cut me a good deal on it all the help you get on here you will have it up and running in no time !! Don’t do the same as me on you tube and scare yourself !!!
He sells all his cars as non runners that’s how I bought mine and I put battery on and 5 gallons of fuel and off it went

mate that’s music to my ears as I’m really taking a gamble and buying without seeing it. I’ve head he is a decent bloke selling them though.
Hopefully won’t take much to get it running as I’m in patient but also looking forward to tug fun of finding things to fix weirdly!

When you looked over it can you remember much else it would of needed. I know I’ll be in need of a rear hatch solenoid (I’ll have to get in touch with Keith for that) also think it’s missing a rear interior trim for pictures.